Shotgun

A shotgun throws a pattern rather than a bullet, and almost every rule it has follows from how wide that pattern is at the moment it arrives. All shotguns take +25 at point blank and short range — on top of the point-blank class bonus when that close — and resolve their criticals on Ballistic Shrapnel RMUWeapon Law: Firearms p. 12, section 3.5: every shotgun takes +25 inside its two nearest bands, stacking with whatever the range itself is worth, and sends all of its criticals to the Shrapnel table.

The pattern widens about 3' every 120' of range. Anyone else caught in the cone — not the person aimed at — faces the same attack roll stripped of the attacker's skill bonus, against their own DB RMUShotgun spread, Option 1 (Weapon Law: Firearms p. 12): a typical spread is about 3' at 120', and any creature in the cone other than the original target faces the original roll unmodified by the attacker's skill, against their own DB. The book gives that width at one distance; reading it as a steady rate from the muzzle, which is what the figure draws, is this conversion's, and 'typical' is the book's own word - a choke changes it (Fig. 1).

That is a choked gun. A hunting barrel narrows at the muzzle to hold its pattern together. A riot gun or a sawn-off barrel has no choke to hold it and opens about half again as fast — call it 4.5' every 120', so a little over a foot across at 30' where a choked gun throws three quarters of one RMUWeapon Law gives one spread figure and does not mention choke. Published choke-and-pattern tables put a full choke at about 1 inch of pattern per yard and a cylinder bore at about 1.4, with a further 5 inches of width already present at the muzzle - so the book's 3' at 120' is a FULL choke, the tightest of the four, and the open end of the range is around half again as wide. Carrying that into a second rate is this conversion's, and it is why a sawn-off spreads faster rather than slower.

Fig. 1 How wide the pattern gets

How wide the pattern gets

Distance runs across; the circles are the pattern, drawn to a scale of their own — at the axis's scale the near ones would be invisible. The open barrel is half again the choked one at every mark. Even at 30' the choked pattern is under a foot across — closer than that it is narrower than the person being shot at, which is the whole argument for resolving a shotgun as a slug at point blank. The last mark is the book's own reference: 3' at 120'.

Distance runs across; the circles are the pattern, drawn to a scale of their own — at the axis's scale the near ones would be invisible. The open barrel is half again the choked one at every mark. Even at 30' the choked pattern is under a foot across — closer than that it is narrower than the person being shot at, which is the whole argument for resolving a shotgun as a slug at point blank. The last mark is the book's own reference: 3' at 120'.

At point blank the pattern has barely opened, so the shot arrives as one mass: resolve it as a slug, keeping Shrapnel criticals. That is true of any shotgun, not only a sawn-down one RMUShotgun Option 2 (Weapon Law: Firearms p. 12): because the Shotgun Table Modification Chart is built on the spread, every shot size is treated as a slug at point blank, resolved as a slug but keeping Shrapnel criticals. It is a general shotgun rule; Option 3 extends it to short range for sawed-off barrels only.

Sawing the barrel takes the choke with it. A sawn-off keeps the point-blank slug treatment every shotgun has — SG table number +1, criticals still Shrapnel — and gets nothing beyond it: past point blank it throws the open pattern above, wider than a choked gun's at every distance. Its SG number also drops by 1 to 4 by how much barrel is gone RMUThe table drop of 1 to 4 and the +1 slug row are the Shotgun Table Modification Chart (Weapon Law: Firearms p. 12), kept as written. RAW's Option 3 also extends the point-blank slug treatment to SHORT range for a sawed-off, and this conversion does not: the choke is what holds a pattern together, so removing it makes the shot open FASTER than a choked gun's, not slower. At short range an unchoked pattern is already wider than the target it is fired at, which is the opposite of a slug. The wider spread is the drawback the barrel buys instead.

The action economy, cover, and everything a shotgun shares with the other guns are on Combat. The attack matrices for this weapon are not built yet.